Find a contractor who comes with excellent references. Duct cleaning can be a long, arduous process that requires a contractor to spend a lot of time in your home.

You want to find out if the contractor is professional and courteous before you hire him or her for the job. References give you the best idea of what to expect from the contractor once work is underway.

You should always get an estimate from a few different contractors before you hire someone. These estimates will allow you to shop around for the best prices and can go a long way toward saving you money. You can also potentially use these estimates to bargain for better prices with other contractors.

If your contractor asks for a deposit, then he or she shouldn't ask you to pay more than 25 or 30 per cent of the total estimated cost.